iodine crystals are listed in Title 21 Code of Federal Regulations, Part 1300 as part of the Comprehensive Methamphetamine Control Act. The Federal Government requires that manufacturers and distributors of any chemicals/product listed within Part 1300 (on List I or List II or otherwise identified) to properly register with the DEA and state agencies. The requirement governs amounts of 13.5 oz or more for every purchase.
California Health & Safety Code Section 11107.1 further restricted iodine crystals by requiring reporting and recordkeeping of all iodine crystal sales regardless of the amount. Additionaly, iodine crystal sales are limited to 8 oz every 30-days for individuals. This became effective January 1999.
Learn more at www.usdoj.gov/ndic